The present invention pertains to the fields of connectors for electrical and of optical signal-bearing lines. More particularly, the present invention pertains to a connector for simultaneously connecting both optical fibers and multi-conductor electrical lines.
Multi-element electrical connectors for simultaneously connecting several low frequency (including DC) current-carrying conductors (i.e. two electrical lines each including several current-carrying conductors) are well known in the art. Such multi-element connectors often include a plug member and a socket, with one of the connector members having several contact-carrying wells or recesses, and the other connector carrying corresponding upstanding metal pins or rods arranged to slidably register with the respective recesses.
The prior art also includes connectors for connecting optical fibers. An optical fiber typically consists of a core of dielectric transparent material surrounded by a layer of transparent cladding material having a refractive index lower than that of the core. An optical fiber connector joining two lengths of optical fiber is intended to arrange that light energy will propagate from one of the lengths to the other without appreciable loss, i.e. without what is called insertion loss that occurs when light is inserted by the connector into the other fiber. To keep insertion loss low when connecting ends of two optical fibers, it is important to register the centers of the fiber end faces, and to precisely align the fibers where they are joined, and also to have the joined ends abut over the entire surface of each end with at most a small gap (not necessarily a gap of air). To the extent that the connection provides essentially a direct continuation of the optical fiber material from one fiber length to the next, without any appreciable intervening gap, the insertion loss is minimized.
U.S. Pat. No. 4,458,985 discloses a field-installable optical fiber connector, consisting of two identical halves, each coined or stamped in a high precision manufacturing operation so as to ensure that the optical fiber lengths being joined are both precisely aligned and their end faces abut each other with at most a small gap. Each coined or stamped connector half includes a trench with a pair of parallel, resilient supporting rails for holding the respective optical fiber centered in the trench. Each connector half also has coined into a surface a pair of alignment holes and a pair of mating protuberances; the holes and protuberances are separated from each other so as to aid in aligning, and are of a shape and size to mate when the connector halves are mated. An optical fiber in a connector half is secured in place by staking or hot upsetting.
The prior art further includes a multi-conductor/ coaxial electrical connector for simultaneously connecting a multi-conductor and a coaxial cable. For example, U.S. Pat. No. 3,154,360 provides a plug member and a socket (receptacle) member. The plug member includes a cylindrical shank having diametrically opposite longitudinally extending flats on which there are contact elements. A set of contact elements are provided as longitudinally spaced, transversely extending arcuate conductor strips embedded in the shank and coplanar with the curved surfaces of the shank. Two opposite longitudinally extending sets of such contact elements are provided, each set being disposed between the flats. A coaxial conductor collar and pin project forwardly of the leading end of the shank and are connected respectively to a tubular conductor and a coaxial conductor housed in the shank. The contacts and the collar and pin are connected to corresponding conductors and a coaxial line or, alternatively, there is provided a post directed coaxially rearwardly of the shank and carrying connector lugs and a coaxial connector connected respectively to the contact elements and to the collar and pin.
The socket member includes a longitudinally extending body member having a cylindrical cavity. At the base of the body member is mounted a coaxial collar and sleeve structure that is slidably engageable with the plug-mounted collar and pin. The socket includes a set of contact elements defined by resilient contacts disposed in recesses formed in the face of the socket member cavity and corresponding in location to the plug contact members. An orienting means is provided for maintaining a predetermined angular orientation between the plug and socket members during relative sliding coupling and permitting relative rotation when the plug member has been inserted to the maximum depth permitted by the socket member. The orienting means includes at least one longitudinally extending groove formed in the cavity face of one of said socket and plug members and a protuberance corresponding in shape to the cross-section of the respective groove and located at the leading and trailing ends of the other of said plug and socket members. Each longitudinal groove joins adjacent to its leading and trailing end a circumferentially extending groove of limited length.
What is still needed is a connector for simultaneously connecting several low frequency current-carrying conductors (including DC) and also two ends or more of optical fiber.
Accordingly, the present invention provides an electro-optical connector consisting of a plug and a socket, each bearing both a multi-conductor and at least one optical fiber, and when in intercoupled condition, provides a connection for both the multiconnectors of the plug and socket, and also for the at least one optical fibers of the plug and socket. The socket has an elongated longitudinally extending cavity formed therein, and a plurality of longitudinally spaced mutually insulated first contact elements disposed within the cavity. The mating plug slidably registers with the cavity between advanced and retracted positions and has a leading end directed toward the base of the cavity. In addition, there are a plurality of longitudinally spaced, mutually insulated second contact elements disposed along the plug, and means maintaining a predetermined angular orientation between the plug and socket during relative sliding of the plug and socket, and permitting relative rotation of the plug and socket at the plug advanced position. The first and second contact elements are out of engagement at the predetermined angular orientation and in engagement upon rotation in a single predetermined sense from the predetermined angular orientation to a closed contact position. Separable collar members and optical fiber lengths are coaxial with and extend to the leading end of the plug and to the base of the cavity, and so define an optical fiber connector. The optical fiber connector is in a coupled condition when the plug is in its cavity advanced position.
In a further aspect of the invention, one of the collar members nests in the other of the collar members when the plug is in the advanced position.
In another, further aspect of the invention, the electro-optical connector includes a plurality of longitudinally aligned sets of the longitudinally spaced second contact elements and a corresponding plurality of longitudinally aligned sets of the first longitudinally spaced contact elements, and the peripheries of the sets of second contact elements are of arcuate configuration and extend circumferentially of the plug for less than 360xc2x0 and in a straight line, lengthwise of the connector.
In another, further aspect of the invention, the socket includes a well portion defined by a cylindrical wall, the inner surface thereof having longitudinally spaced recesses formed therein, the first contact elements being located in the recesses and normally projecting above the upper edges thereof and being resiliently inwardly urged by the second contact elements during engagement therewith, and including lugs connected to the first contact elements and projecting through the cylindrical wall.
In another, further aspect of the invention, the orienting means is defined by at least one longitudinally extending groove formed in one of the connector members and at least one slidably engaging protuberance mounted on the other of the members.
In another, further aspect of the invention, the plug and socket each further include an optical fiber retainer substantially cylindrical in form, the plug optical fiber retainer extending along the length of the plug to the leading end of the plug, and the socket optical fiber retainer extending along the length of the socket to the base of the cavity. Each each optical fiber retainer in turn includes at least four resiliently pliable rails extending along the length of the optical fiber retainer, the four rails so shaped and so positioned so as to exert a radial force tending to center and align the optical fibers so as to be coaxial with the optical fiber retainer.
In a still further aspect of the invention, the optical fiber retainers of the plug and socket also include teeth projections, the plug teeth projections angled toward the leading end of the plug, and the socket teeth projections angled toward the base of the cavity, the teeth projections thereby providing resistance to any backing out of the optical fiber within the plug optical fiber retainer away from leading end of the plug, or within the socket optical fiber retainer away from the base of the cavity.